Many people ask if it is alright to keep just one rabbit and most are worried that their rabbits feel lonely. I always believe that if one does not intend to breed their pets, it is always good to keep just one. It is to spend all time and attention on just one pet. The pet itself will thrive. I do not advice particularly this for rabbits but also for other type of pets as well.
As for rabbits, most of the time when 2 unaltered (not neutered/spayed) rabbits of the same sex are housed together, they will fight once they reached sexual maturity. And if 2 rabbits of opposite sexes are housed together, the outcome would be having far too many rabbits that one could handle. That is beside the point and I have made previous posting regarding my views on breeding.
So my answer to the question if one should keep rabbits in pair to solve what we perceive as loneliness is that they should not keep rabbits in pairs. It is totally alright to keep just one.